aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sparc/lib/mcount.S
blob: 7ce9c65f3592a7f949bffc47ecf558ffbfcc3c3e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
/*
 * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
 *
 * This file implements mcount(), which is used to collect profiling data.
 * This can also be tweaked for kernel stack overflow detection.
 */

#include <linux/linkage.h>

#include <asm/ptrace.h>
#include <asm/thread_info.h>

/*
 * This is the main variant and is called by C code.  GCC's -pg option
 * automatically instruments every C function with a call to this.
 */

#ifdef CONFIG_STACK_DEBUG

#define OVSTACKSIZE	4096		/* lets hope this is enough */

	.data
	.align		8
panicstring:
	.asciz		"Stack overflow\n"
	.align		8
ovstack:
	.skip		OVSTACKSIZE
#endif
	.text
	.align		32
	.globl		_mcount
	.type		_mcount,#function
	.globl		mcount
	.type		mcount,#function
_mcount:
mcount:
#ifdef CONFIG_STACK_DEBUG
	/*
	 * Check whether %sp is dangerously low.
	 */
	ldub		[%g6 + TI_FPDEPTH], %g1
	srl		%g1, 1, %g3
	add		%g3, 1, %g3
	sllx		%g3, 8, %g3			! each fpregs frame is 256b
	add		%g3, 192, %g3
	add		%g6, %g3, %g3			! where does task_struct+frame end?
	sub		%g3, STACK_BIAS, %g3
	cmp		%sp, %g3
	bg,pt		%xcc, 1f
	 nop
	lduh		[%g6 + TI_CPU], %g1
	sethi		%hi(hardirq_stack), %g3
	or		%g3, %lo(hardirq_stack), %g3
	sllx		%g1, 3, %g1
	ldx		[%g3 + %g1], %g7
	sub		%g7, STACK_BIAS, %g7
	cmp		%sp, %g7
	bleu,pt		%xcc, 2f
	 sethi		%hi(THREAD_SIZE), %g3
	add		%g7, %g3, %g7
	cmp		%sp, %g7
	blu,pn		%xcc, 1f
2:	 sethi		%hi(softirq_stack), %g3
	or		%g3, %lo(softirq_stack), %g3
	ldx		[%g3 + %g1], %g7
	cmp		%sp, %g7
	bleu,pt		%xcc, 2f
	 sethi		%hi(THREAD_SIZE), %g3
	add		%g7, %g3, %g7
	cmp		%sp, %g7
	blu,pn		%xcc, 1f
	 nop
	/* If we are already on ovstack, don't hop onto it
	 * again, we are already trying to output the stack overflow
	 * message.
	 */
	sethi		%hi(ovstack), %g7		! cant move to panic stack fast enough
	 or		%g7, %lo(ovstack), %g7
	add		%g7, OVSTACKSIZE, %g3
	sub		%g3, STACK_BIAS + 192, %g3
	sub		%g7, STACK_BIAS, %g7
	cmp		%sp, %g7
	blu,pn		%xcc, 2f
	 cmp		%sp, %g3
	bleu,pn		%xcc, 1f
	 nop
2:	mov		%g3, %sp
	sethi		%hi(panicstring), %g3
	call		prom_printf
	 or		%g3, %lo(panicstring), %o0
	call		prom_halt
	 nop
1:
#endif
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
	mov		%o7, %o0
	.globl		mcount_call
mcount_call:
	call		ftrace_stub
	 mov		%o0, %o7
#else
	sethi		%hi(ftrace_trace_function), %g1
	sethi		%hi(ftrace_stub), %g2
	ldx		[%g1 + %lo(ftrace_trace_function)], %g1
	or		%g2, %lo(ftrace_stub), %g2
	cmp		%g1, %g2
	be,pn		%icc, 1f
	 mov		%i7, %o1
	jmpl		%g1, %g0
	 mov		%o7, %o0
	/* not reached */
1:
#endif
#endif
	retl
	 nop
	.size		_mcount,.-_mcount
	.size		mcount,.-mcount

#ifdef CONFIG_FUNCTION_TRACER
	.globl		ftrace_stub
	.type		ftrace_stub,#function
ftrace_stub:
	retl
	 nop
	.size		ftrace_stub,.-ftrace_stub
#ifdef CONFIG_DYNAMIC_FTRACE
	.globl		ftrace_caller
	.type		ftrace_caller,#function
ftrace_caller:
	mov		%i7, %o1
	mov		%o7, %o0
	.globl		ftrace_call
ftrace_call:
	call		ftrace_stub
	 mov		%o0, %o7
	retl
	 nop
	.size		ftrace_caller,.-ftrace_caller
#endif
#endif